27 VCE_EuropaBrücke

SAMCO Final Report 2006
F04 Case Studies
Europabrücke - Austria
Project Description:
Bridges are ageing and traffic is growing, which creates a demand for accurate fatigue life
assessment. The Europabrücke – a well known Austrian steel bridge near Innsbruck,
opened in 1963 - is one of the main alpine north-south routes for urban and freight traffic. A
long-term preoccupation of VCE with BRIMOS (BRIdge MOnitoring System) on the
Europabrücke (since 1997) and the assessed prevailing vibration intensities with regard to
fatigue problems and possible damage led to the installation of a permanent measuring
system in 2003. Today’s monitoring abilities enable us to measure performance precisely.
High-precision sensor data of accelerations, velocities, displacements in dependence of
separately registered wind and temperature data and their implementation into analytical
calculation provide the possibility to realize lifetime considerations, which are of eminent
importance for bridge operators.
Europabrücke, Innsbruck, Austria
Description of Structure & Monitoring System
Previous measurements at the Europabrücke matched very well with the comparative
analytical calculations, but they also exhibited the remarkable loading impact. Currently the
bridge is stressed by more than 30000 motor vehicles per day (approximately 20% freight
traffic). The superstructure is represented by a steel box girder (width = 10m; variable
height along the bridge-length 4,70 – 7,70 m) and an orthotropic deck and bottom plate.
This motorway bridge with six spans differing in their length (longest span 198m, supported
by piers with an elevation of 190m) and a total length of 657 m comprises six lanes, three
for each direction distributed on a width of almost 25 meters.
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SAMCO Final Report 2006
F04 Case Studies
Quick Facts:
• Name and Location: Europabrücke, Innsbruck, Austria
•
Operator: ASAG (Alpenstrassen AG), Austria
•
Structure category: large span bridge
•
Spans: 6 spans: 81/ 108/ 198/ 108/ 81/ 81 m
•
Structural system: Steel box girder with orthotropic deck and concrete columns
•
Start of SHM: May, 1998
•
Number of sensors installed: 24
•
Instrumentation design by: VCE, Vienna Consulting Engineers, Austria
The monitoring system itself consists of 24 measuring channels (sampling rate 100
Hz) representing the main span’s, the pier’s and the cantilever’s accelerations, the
abutment’s dilatation, wind speed and direction, and temperatures at several
locations.
WL PATSCH
WL SCHÖNBERG
Purpose of Inspection:
The superior goal is to determine the relation between the randomly induced traffic
loads (vehicles per day) and the fatigue-relevant, dynamic response of the structure.
As life-time predictions in modern standards depend on lots of assumptions, the
emphasis is to replace all these guesstimates by measurements. In that context it is
going to be focused on three ranges:
•
•
•
Global behavior in dependence of all relevant loading cases
Cross-sectional behavior under special consideration of the cantilever regions
Local systems analyzing the interaction between tires and the beam-slab
connections
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Page 2 of 6
SAMCO Final Report 2006
F04 Case Studies
In each of these levels of analysis the consumption of the structure’s overall-capacity
per year is to be determined.
Additionally to fatigue assessment, new compensation methods for assessment &
compensation of environmental conditions (temperature, additional mass
loading,…) in frequency analyses are developed. This opens new possibilities for
structural management and lifetime prediction as well as for more accurate damage
detection.
Sensor Details:
Type of sensors
Number
Location
Displacement sensors
2
at both abutments
1D-acceleration transducers
3
at the cross section’s cantilevers
3D-acceleration transducers
3
orthotropic bottom plate
Wind sensors
1
5m above the road surface
Temperature sensors
7
inside & outside the box girder
Measurement Equipment and Data Management:
Type of system
PC & remote
access - based
measuring system
Data Management
automatic report generating at the end of each week
Storage in a long term data base on site
More detailed analysis (statistics, frequency analysis…) and
graphical presentation and documentation in office
notification via modem about the successful operation of the
measuring system
Data Analysis Procedures:
Type of analysis
Ambient vibration
monitoring, Fatigue
assessment based on
rainflow analysis &
statistics, assessment &
compensation of
environmental conditions,
damage detection and
lifetime calculations
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Software
Additional features
Self made software,
RFEM
no expert system
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SAMCO Final Report 2006
F04 Case Studies
Examples of Outcomes
- Assessment & Compensation of Environmental Conditions
1. Eigenfrequency
Temperature
00:00:00
00:00:00
Time
22:00:00
22:00:00
20:00:00
20:00:00
18:00:00
18:00:00
16:00:00
16:00:00
14:00:00
14:00:00
12:00:00
12:00:00
10:00:00
10:00:00
08:00:00
08:00:00
06:00:00
06:00:00
04:00:00
04:00:00
02:00:00
Time
02:00:00
[°C]
[Hz]
00:00:00
00:00:00
0,710 0,720 0,730 0,740 0,750 0,760 0,770
0,0
5,0
10,0
15,0
20,0
25,0
Pattern of the main span’s stiffness and its obvious dependency on temperature (daily cycle)
Temperature - Base Point - box girder (from 07-03-2003 until 20-05-2005)
[°C]
38
33
28
23
18
13
8
3
-2
-7
Max = +36,25 °C
Min = -15,58 °C
-12
(04-08-2003)
(01-03-2005)
25.04.2005
26.03.2005
24.02.2005
25.01.2005
26.12.2004
26.11.2004
27.10.2004
27.09.2004
28.08.2004
29.07.2004
29.06.2004
30.05.2004
30.04.2004
31.03.2004
01.03.2004
31.01.2004
01.01.2004
02.12.2003
02.11.2003
03.10.2003
03.09.2003
04.08.2003
05.07.2003
05.06.2003
06.05.2003
06.04.2003
07.03.2003
-17
Pattern of temperature at the bridge’s basing point (assessment period 2 ½ years)
mm
Vergleich der gemessenen und rechnerischen Verschiebung ∆u
an der DMA1 Europabrücke vom 05.03.2004 - 20.05.2005
100,00
40
30
50,00
20
0,00
10
-50,00
0
-100,00
-10
∆u gem. korr.
Hüllkurve unten
Hüllkurve oben
Temperatur Hohlkasten
-20
05.03.2004
12.03.2004
19.03.2004
26.03.2004
02.04.2004
09.04.2004
16.04.2004
23.04.2004
30.04.2004
07.05.2004
14.05.2004
21.05.2004
28.05.2004
04.06.2004
11.06.2004
18.06.2004
25.06.2004
02.07.2004
09.07.2004
16.07.2004
23.07.2004
30.07.2004
06.08.2004
13.08.2004
20.08.2004
27.08.2004
03.09.2004
10.09.2004
17.09.2004
24.09.2004
01.10.2004
08.10.2004
15.10.2004
22.10.2004
29.10.2004
05.11.2004
12.11.2004
19.11.2004
26.11.2004
03.12.2004
10.12.2004
17.12.2004
24.12.2004
31.12.2004
07.01.2005
14.01.2005
21.01.2005
28.01.2005
04.02.2005
11.02.2005
18.02.2005
25.02.2005
04.03.2005
11.03.2005
18.03.2005
25.03.2005
01.04.2005
08.04.2005
15.04.2005
22.04.2005
29.04.2005
06.05.2005
13.05.2005
20.05.2005
-150,00
Comparison of assessed & expected horizontal bridge deformations in dependence of
temperature
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SAMCO Final Report 2006
F04 Case Studies
Wind velocity-analysis for a certain month
In each of the already described levels of fatigue analysis performed by means of
Rainflow-Counting, damage-accumulation, global and local Finite Element Analysis
& statistical consideration. The detailed knowledge about the progression of the
prevailing traffic from the very beginning up to these days and the implementation of
published future trend studies for the next ten years can be used for an
extrapolation of the measured impact for the whole lifetime.
mm
17.52
27161
10000
Ereignisse (logarithmisch)
27161
10000
1000
1000
Min
100
0
10
1
17.52
-17.52
mm
mm
0
0
Min
Max
-17.52
17.52
-17.52
17.52
1
8
2
2
5
2
1
2
+
50 +
39 +
24 +
20 +
17 +
9 +
8 +
6 +
5 +
3 +
1 3 +
5 +
4 +
4 1
100
+
+ +
+ + +
+ + + +
+ + + + +
+ + + + + +
9478 66 90 + + +
2720 21 19 + + + +
1812 2 8 28 + + + +
4 1 4 4 5 + + + 9678
3
3 2 2 15 + + 7859 60
2 1 1
2
+ 66 6551 2923
1
1 18 + + + 8755 50
10
1
0
-17.52
Max
mm
Rainflow Matrices for counting of recurring fatigue-relavant impact cycles
Damage assessment via implementation of measurements into Finite Element-Models
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SAMCO Final Report 2006
F04 Case Studies
References
1. Wenzel, H., and D. Pichler. 2005. “Ambient Vibration Monitoring,” J. Wiley
and Sons Ltd., Chichester - England, ISBN 0470024305
2. Veit R., H. Wenzel and J. Fink. 2005. “Measurement data based lifetimeestimation of the Europabrücke due to traffic loading - a three level
approach”, In International Conference of the International Institute of
Welding. Prague.
3. H. Wenzel, R. Veit, H. Tanaka.: “Damage detection after condition
compensation in frequency analyses” in “Proceedings of the 5th
International Workshop on Structural Health Monitoring”, Stanford,
September 2005
Submitted by:
Vienna Consulting Engineers (VCE)
A-1140 Vienna, Austria
60 Hadikgasse
Phone: +43(1) 8975339-1420
Fax: +43(1) 8975339-2420
Email: [email protected]
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